(a) Field of the Invention
The present invention relates to a terminal and an operation method thereof in a multi-user multi-input multi-output system.
(b) Description of the Related Art
After 4G, mobile communication systems require a 1000 times higher frequency efficiency, a 1000 times higher energy efficiency, and a 1000 times higher acceptance increase of device due to a rapid increase in data traffic, compared to those of a 4G system such as 3GPP LTE. As physical layer technologies for increasing the frequency efficiency, there are a network MIMO, an interference alignment, a relay network, a heterogeneous network, a large-scale antenna, a multi-user MIMO, etc.
The multi-user MIMO system is a technology for allowing a base station to use the same resource to simultaneously provide services to a plurality of terminals (users) within a single cell. In the multi-user MIMO system, there is a need to obtain channel state information to allow the base station to perform a multi-input multi-output (MIMO) transmission through a plurality of antennas. To obtain the channel state information, many reference signals and radio resources for channel state information feedback are required.
Further, in the multi-user MIMO system, there is a problem in that scheduling and precoding computation complexity is increased due to an increase of the number of users who may be simultaneously accepted
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.